CVE-2026-5720 miniupnpd Integer Underflow SOAPAction Header Parsing

What is CVE-2026-5720?

CVE-2026-5720 is a high-severity vulnerability in miniupnpd, published on 17 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.

Weakness: CWE-191, CWE-125

Which versions are affected by CVE-2026-5720?

It affects 1 product.

Products include Miniupnp Project Miniupnpd.

How do I fix CVE-2026-5720?

Apply the vendor's patch.

Is CVE-2026-5720 being exploited?

There is no known exploitation of CVE-2026-5720 in the wild and no public exploit code.

Other vulnerabilities in miniupnpd

• CVE-2013-0230 Memory corruption in n/a Critical 10.0
• CVE-2017-8798 Integer overflow in n/a Critical 9.8
• CVE-2017-1000494 Memory corruption in n/a High 7.8
• CVE-2013-0229 Denial of service in n/a High 7.8
• CVE-2013-1461 Null dereference in n/a High 7.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2026-5720, GHSA-q4xv-xmjx-4h94, UBUNTU-CVE-2026-5720, USN-8731-1.